M695 / S2R800 / M696 clutch parts (all APTC type)

[scott_araujo]

Ah!  Thanks, that was really puzzling.  Especially since it didn't 'slip' on my last bad downshift.

Scott

[rule62]

FWIW, there's one on fleaBay that'll fit the OP's bike.  Ends in about 2 hours at (Dec 21, 200918:38:16 PST)

At only $130, if I were the OP, I'd throw that one in place of the APTC and then wait until it starts slipping to buy a regular ole' wet clutch pack.  Forget the APTC entirely. 

http://cgi.ebay.com/ebaymotors/COMPLETE-CLUTCH-BASKET-DUCATI-750-SS-2000-00-01-99-900_W0QQcmdZViewItemQQhashZitem53de9c06fcQQitemZ360217052924QQptZMotorcyclesQ5fPartsQ5fAccessories

[somegirl]

I notice clutch slip when I get my bike back from nichols also.

Just as another data point, I have never had clutch slip on my bike, and all my services (except a couple of oil changes at home) have been at nichols.

[scott_araujo]

Found a little info on the '04 bikes with APTC:

http://www.sportrider.com/bikes/2004/146_04_ducati_aptc_clutch/index.html

At least according to this the same springs were used on all bikes 620 and larger with 40% less lever effort from previous models like my '03.

Scott

[BK_856er]

Found a little info on the '04 bikes with APTC:

http://www.sportrider.com/bikes/2004/146_04_ducati_aptc_clutch/index.html

At least according to this the same springs were used on all bikes 620 and larger with 40% less lever effort from previous models like my '03.

Scott

Thanks for posting the link - interesting read.  Too bad they didn't go into greater mechanical detail.  Scott, I think you meant to write that "the same springs were used on all bikes 620 and larger WITH APTC."  I spot-checked the part diagrams and as far as I can tell all ducatis with an APTC clutch (2004-2009) use the same clutch parts and springs.  The other wet and dry cluches use different springs.

Some factoids from the article:

- normal ducati pressure plate compression force = 860N
- APTC pressure plate comporession force = 560N
- normal ducati clutch disc diameter = 150mm
- APTC clutch disc diameter = 140mm
- maximum clutch torque for both types = 9.98 Nm

And this interesting bit:  "A unique technical solution has allowed the creation of a clutch in which the transmittable torque is, in part, independent from the pressure of the clutch springs."  So maybe I'm barking up the wrong tree looking for stronger springs to minimize slippage?

BK

[rule62]

"A unique technical solution has allowed the creation of a clutch in which the transmittable torque is, in part, independent from the pressure of the clutch springs."  So maybe I'm barking up the wrong tree looking for stronger springs to minimize slippage?

BK

Heavier clutch springs will help a bit. Once you take apart the APTC, you'll see that there are some other little springs between the plate and the slipper hub. When "back-torque" is applied they work against the main springs to allow the clutch to slip. Heavier main springs will limit the amount of slippage.

[scott_araujo]

BK, yes, with APTC.  Thanks for the correction, that's what I meant.  And yeah, interesting read but I wish there were some more technical details on exactly how it works too.

Scott

[Speeddog]

The grooves in the hub (that the steels engage) are cut at an angle, so under power, they clamp the plates tighter, and on overrun/closed throttle, they push the plates apart.

Same fundamental principle as a conventional slipper clutch, just a different execution.

[BK_856er]

The grooves in the hub (that the steels engage) are cut at an angle, so under power, they clamp the plates tighter, and on overrun/closed throttle, they push the plates apart.

Same fundamental principle as a conventional slipper clutch, just a different execution.

That helps explain why the pressure plate spring tension is less important than on a standard clutch - forward torque should squeeze the plates together.  I could not easily locate a good picture of the hub, but the following video (non ducati adige aptc) clearly shows the angled grooves.  I kinda like the APTC setup.

APTC Video Assembly

BK

[rule62]

I kinda like the APTC setup.

I like it a lot better in theory than in practice. 

BTW:  I've got an extra APTC assembly lying around if anyone's interested.

[BK_856er]

Status update:

Clutch hydraulics.  The shop bled the clutch as part of the service, but I did it again anyway and used their fluid brand - just a few tiny bubbles came out.  Fluid action in the reservoir looked good.  I also dropped the fluid level to the min line for the fun of it (more headspace).  The piston free play was in spec when hot, but I backed out the CRG adjuster pin a little anyway.  No real change on the 75-mile test run.

Motor oil.  I changed back to my usual Mobil 1 MX4T 10W40 full synthetic.  While I was draining the oil I noticed that both tank vent lines were severely kinked under the tank.  Maybe some of my issue was fueling?  Also caught what looks like the very beginning of a vertical cylinder cam seal leak.  50-mile test run today went well and I could not induce clutch slippage on hard WOT.  I did notice that the clutch didn't seem to bite too hard on hard acceleration upshifts, so maybe things really are starting to wear, or that's just the nature of the (APTC) beast and I didn't pay attention to it before.  I'll get some more miles in before I decide if I need to do anything else.  For now I'm good to go.

So, like DarkStarR, my 15k mile APTC clutch does not pair well with the shop oil.  I'm sure it's a fine oil and I'm not knocking it, but my clutch slips less with MX4T.  As a reminder, the slippage I was experiencing was ONLY under relatively extreme conditions and not something that would be noticed in casual use.

I talked to the shop before I took the steps above and they were very interested in hearing about the oil outcome.

BK